Vehicle drive control



April 29, 1952 H. O. SCHJOLIN VEHICLE DRIVE CONTROL 3 Sheets-Sheet 1Original Filed Oct. 21, 1945 ZSnventor Gttbmegs April 1952 H. o.SCHJOLlN 2,594,811

VEHICLE DRIVE CONTROL Original Filed Oct. 21, 1943 3 Sheets-Sheet 2Gttomeg April 1952 H. o. SCHJOLIN VEHICLE DRIVE CONTROL 3 Sheets-Sheet 3Original Filed 001;. 21, 1943 Gttomegs Patented Apr. 29, 1952 VEHICLEDRIVE CONTROL Hans 0. Schjolin, Birmingham, Mich., assignor to GeneralMotors Corporation, Detroit, Mich., a

corporation of Delaware Original application October 21, 1943, SerialNo.

507,204, now Patent No. 2,435,930, dated February 10, 1948. Divided andthis application August 21, 1945, Serial No. 611,789

26 Claims. 1

The invention herein relates to motor vehicles,

and especially to an improved compact grouping of driving mechanism forlarge heavy duty vehicles such as buses, trucks, and those of militarynature.

In order to arrange the driving mechanism in a small space, fordetracting least from the useful load space, the present inventiontherefore embodies a special drive arrangement for imparting the torqueto the vehicle Wheels with a minimum loss of power conversion,accomplished by mounting the entire torque multiplying mechanism at anangle to the engine shaft. By this arrangement, differing radically fromothers, the direct drive clutch shift and control elements are locatedseparately, compartmented from, and at one side of the torque converter,accessible for repair and replacement. The net space saving achieved bythe invention, in rear-engined vehicles is considerable.

A further advantage is an arrangement which lends itself to variationsin form and size of torque converters to be used, and in the selectionof different engines and input gear driving ratios to suit space andpower requirements for given vehicles, so as to make it possible toutilize the same fundamental output gear and shafting combination withdifferent drive units. By this means, if it be desired to use either agasoline engine or a slower running diesel having a difierent type ofpower curve, but with the same peak horse power, the same converter maybe used without distributing the remainder of the drive, while obtainingthe best performance from the converter with-either engine. It is alsoto be observed that with the present arrangement, the dimensions of theangle drive gears and bearings are much reduced as compared with earlierarrangements,.since in the present invention-the gears are only requiredto handle engine torque.

rather than load torque. A further advantage is derived from the factthat the center of gravity in the present drive unit is much closer tothe engine, than in standardized installations, and

that the net torque reaction to be taken is of low value as well asbeing exerted through a shorter lever arm, cutting down shock loads frompropeller shaft thrust.

tion, clutch. assembly. This facilitates the speed hat which aconverteror clutch unit may be, serv iced in the garage or in the field so thatthe vehicle remains in operation over a longer period without servicedelay. The remainder of the drive for the most part becomes a permanentpart of the vehicle. It is obvious that the reduction in size of thedriving and drive-supporting parts because of the reduction of theloading effect, creates a considerable cost saving, and substantialsaving of overall weight. The whole torque reaction is supported on theengine mounting, likewise an important feature.

By the arrangement described herein, the fluid torque converter driveonly requires a minimum of readily changeable fluid seals, and as willbe seen, the passage of fluid to and from the drive assembly is handledthrough simple openings, one in the rear bearing cap and the otherthrough a casing hole at the periphery of the assembly. A furtheradvantage appears in the fastening of the second stage converter guidevanes of the torque converter directly to the casing. An additionaladvantage lies in the inclusion of the clutch and converter coverportion of the casing with the front bearing of the transmissionassembly, further facilitating disassembly and repair. The location ofthe clutching means in the angular shaft assembly is a distinguishinguseful feature not believed shown in the prior art. The propeller shaftcouples one end of the angular drive assembly to the axle differentialWithout interfering with the spring action 01' mounting.

The foregoing objects and advantages are disclosed in, and the newdriving structure is claimed in the original application to the presentdisclosure, namely Serial Number 507,204 filed October 21, 1943, nowPatent No. 2,435,930, the present divisional application dealing withthe features of the invention pertaining more directly to actuation andcontrol means for the drive mechanism illustrated, but includingreference to such structure when required to state a cooperative unity.

The present disclosure therefore provides a special arrangement ofsimple and compact controls for the shifting of the double clutchdriveratio changing elements, with positive remote station operation bythe driver by appropriate controlling apparatus.

Of particular utility is the arrangement of interlocking controls whichprovides full automatic forward drive with ratio lockout shiftinterconnection so that the vehicle operator retains full control of allratiqshift functions for stopping for reversing." further improvementlies in the novel means described herein for more accurate determinationof automatic ratio changes on the part of th operator, andcorrespondingly improved driver-feel of the operatorconnected elementsparticipating in the automatic ratio change sequences.

Figure l is a partial view of the rear drive plan of the invention for amotor bus. In this figure, the engine E driving through a vibrationdamper D, delivers its torque to the output shaft flange 39* through oneof the clutches of the double clutch assembly C; or through the other ofsaid clutches coupled to a turbine torque converter and through a rollerclutch R, located at a point convenient for inspection and replacement.A gearbox G provides the means for selecting forward and reverse drive,or neutral. In Figure l is shown a universal joint U connected to outputdriving flange 30 and driving a diagonal jack shaft 58, universal joint68 and differential gear 10 which in turn transmits the drive to thevehicle wheels. It will be noted that the only angular conversion ofpower between the engine and the parallel rear axle, other than by thedifferential gear of the axle, is by the power shaft input gearingadjacent the vibration dampener D.

Figure 2 shows in plan detail the structural arrangement of thesupporting and driving parts.

It should be observed that the engine casing,

clutch and converter housings and gear casing are integrally supportedagainst torque reaction. With a right-hand rotating engine, the reactioncouple is downward at the right of the engine, while the adjacentportion of the gearbox G under forward drive sustains a reaction coupleadding to the first.

The casing at the left of the figure has flanged plate Hilly removablefor service or replacement of roller clutch R without disturbing theother drive elements, and the external member of the unit R is removableby releasing bolts (not numbered). The turbine casing Ififlc is joinedto the clutch casing 189a at X by stud bolts or equivalent fastenings,so that the turbine device and its clutches are readily serviced orreplaced without affecting the other more permanent units of the drivemechanism.

Figure 3 is a perspective view in part section of the gear leverinterlock control shown in Figure 4.

Figure 4 is a diagrammatic disclosure of the external controls for thedevice of the invention, showing the means for controlling the structureof Figure 2 automatically, while affording overruling control by theoperator when required.

The structures in the Figures 1 to 3 are for the greater part, thoserequired to illustrate a fullyoperating disclosure of drive mechanism towhich the ratio shift actuation and controls of Figure 4 are applied.

The engine shaft l in Figure 2 terminates in flange {a which is boltedto the driver ring 3 of the friction vibration dampener assembly D, thedriven hub i of which is splined to the transmission input shaft 2, thelatter being formed integral with bevel gear 5 meshing with bevel gear 6of the transmission input sleeve 'l".

The input driving drum 8 is bolted to sleeve 5 and is a part of thedouble clutch assembly C which connects the drive of the engine witheither of driven clutch plates 3! or 32.

The transmission main shaft [9 is splined to accommodate the hub 9 ofclutch driven plate "3!; it extends through the transmission to the leftwhere it is splined to the inner member l8 of the roller clutch assemblyR, and extends to the right where it is splined to drive the combinationgear and jaw clutch 19 of the reversing gear unit G.

The clutch plate 32 isriveted to hub 12 rotating with sleeve H integralwith the impeller [5 of the torque converter unit T. A torque converterunit T shown in section in the present example of Figure 2, is similarto that of my U. S. Letters Patent 2,308,113 filed October 4, 1940, andissued January 12, 1943. The unit consists of three fundamentalelements; an impeller l5, a fixed reaction assembly 16, and a drivenmember H, the latter bein bolted to the external member 18* of theroller clutch assembly R. Collar 60 slides axially to shift the innerradial fingers of clutch plate loading spring. The clutches 3|, 32provide the forward drive-changing means and the associated clutchloading parts in the connections between the lever 62 and the place ofpressure application at plate 63, constitute the drive actuatingmembers, described in detail further below.

At the right of Figure 2 is shown the reverse gear unit consisting of agear train having input member l9, and output gear 25 integral withshaft 30, splined to the output driving flange 36 The gear is mesheswith input counter gear 26 which is rotatable with the counter shaftsection, to which the second counter shaft gear 2! is attached or isintegral. A splined collar 48 which also may be called a slider memberis toothed externally at 43 for meshing with reverse idler gear 22, andis carried on a forward extension of the teeth of gear 25 with which itsinternal teeth 45* mesh. The gear l9 has external teeth Hi which areengaged with the teeth 4i? of the slider at, when the latter is movedinto forward position. The train of the gear unit consists of input gearl9 splined on shaft Ill and constantly meshed with the countershaftgroup Zll, 2| which spins idler 22. The slider 40 carries internal teeth49* which may be driven by teeth ifi of gear !9 when the slider isadvanced to the left as shown in Fig. 2. For reverse shift, the slideris moved to the right, disengaging teeth [9 and meshing teeth 48 withthe teeth of idler 22. Since the torque converter delivers no drivetorque at idle throttle when this shift is made, the shift proceedswithout a need for a neutral dwell so that internal teeth lil of slider40 may shift directly from mesh with w while teeth 40* mesh with idler22. The slider ll! and associated parts include the selective forwardand reverse driving elements. The linkage M, 42, A3, 44 is operated bythe construction shown in Fig. .3.

When the slider is moved toward the rear of the gearbox it establishesthe drive through the reverse train I9, 28, El, 22, 4%! and 25.

In the arrangement and demonstration of the drive noted above, the bevelgears 5 and 6 are related to each other in the ratio of 4 to 5respectively, so that the sleeve 1 and driving drum 8 may rotate at asomewhat slower speed than that of the engine.

The vibration dampener unit D .is arranged ltO permit limited relativemovement between the flange 3 and the hub 4 by virtue of radial slotsfor the bolts 3*, cut in the plate 4 of the hub 4. The slots are ofwider dimension than the diameter of the bolts and the latter arecentered through the action of compressed springs 4 held in apertures inthe retaining plates 4. The

' bolts 3 have adjusting nuts which exert .a given tension forestablishing friction drag between the retaining plates 4 and thecentral flange of the hub 4. Additional friction is obtained by theinclusion of friction washers 4 placed between the external plates andthe central flange and providing a friction force augmented by thetightening of bolts 4 which pass through the assembly at a; shorterradial distance than bolts 3 The permitted clearance for the movement ofthe bolts 4 with respect to the central flanges 4 is obtained by the useof a circumferential slot 4 in flange 4 Belleville washer springs areincluded in the assembly of bolts 4 so that a considerable frictionpreload adjustment can be set up by the operator, an expedient useful,in order to have the apparatus successfully absorb the torque vibrationsof large heavy engines. It will be observed that this device can betuned over a limited range of vibration frequencies by chang ing of theinitial tension provided by bolts 3 and 4 The unusual arrangement of theforegoingdescribed drive has a number of advantages discussed elsewherein this specification. It will be noted that the diagonal casing I Eli!can be completely detached for unit replacement. It is useful that thecasing portion IIIIII may be detachable from I for service to turbineparts, and also that I00 be detachable from IIIII so that differentdesigns or forms of torque converters and clutches can be installed. Itis of primary importance that the casing portion I00 at the leftward endmay be radially detached without disturbing the remainder of the drivingmechanism for the purpose of replacing or adjusting freewheel clutch R.It is further important that the joint at X between casing sectionsII'Ifla and I30?) be provided. It will also be noted that the reversinggear unit G can be separated by ready removal of the casing portion I 00so that whatever infrequent adjustments or replacements are required inthis unit can be readily made, quickly and simply.

In order to accomplish the above successfully, it is essential that thearrangement and gearings to support the shaft and driving partscorrespond with the major axes of drive. To this end bearing III) andbearing I IIl support the transmission inputshaft 2 firmly in the casingsection I 00 The diagonal main shaft I0 is supported in bearings III]and IIll in the casing sections I00 and 10 while the input driving shaftsleeve I is mounted in casing IIJI] and mu in bearings 0 and H0. Therear shaft 30 is piloted by bearing IOI in the inner pocket of gear I9of shaft I 0, and for support in the casing [36 and the flange plate I00by bearing II I). The torque converter sleeve II is supported in webIIlIl of the casing section IIlIl by hearing III), and thecircumferential guide rings for the impeller I such as shown in Figure 2may provide support in web I00 The sleeve 60 of the clutch operatingmechanism is mounted to slide on an extension of the web I00 forsupporting the leftward .portion of hub I2 and the sleeve II, and thedouble-row bearing I03 of Figure 2 may align the turbine rotor I! withrespect to the shaft I0 and the roller clutch inner input I8.

The arrangement of the present demonstration includes the seal I04between theturbine and the hub impeller I5 and the flange of IO; theseal I05 located between the hub of impeller I5 and the web H30 of thecasing; and the seal I06 prevents leakage of grease through the shaft.ing and the extension of web IOIi into the comrotate in the sidewall ofthe casing I00 as shown in Figure 2. The cam is rotated by arm 62reciprocated by the piston I0 shown in section in Figure 4. A method ofoperation of this double clutch control apparatus is described in my U.S. Letters Patent No. 2,308,113, filed October 4, 1940, and'issuedJanuary 12, 1943, and shown in Figure 6 of that patent.

Fig. 2 shows in detail the relationship of the parts operated by theclutch actuator mechanism to provide alternate drive by the clutch drum8 of the clutch discs 3| and 32, acting asthe forward drive-changinmeans.

Engine-connected gear 6 and sleeve I support and drive the presser plate33 in its gripping of disc 3! or disc 32. Shaft III carries splined hub9 and disc 3I equipped with proper facings. Rotating on shaft I0 ishollow shaft II attached to splined clutch hub I2 of disc 32 which alsohas proper friction facings.

Shaft I may drive shaft 9 directly thru clutch disc 3| or indirectlythru the torque converter unit shown at the left of Fig. 2, by clutchdisc 32.

The clutch control and actuator mechanism consists of fittings 34 boltedto member 8, arranged to restrain the external edges of compound discspring 63, the inner edges of which may be shifted to the right or tothe left by movement of bearing sleeve 60 and sleeve 60 longitudinallythrough eccentric 6i moved from outside the gear casing by lever 62.

The fulcrum action is provided by studs 35 and members B 8 Presser plate8 carries studs 25 passing thru apertures in disc spring 63, the studssupport ring 8', while the outward facing portions of 8 and 8 are shapedto bear against the faces of spring 63 located between them.

The fittings 34 are attached to bolt 36 headed in the outer portion ofpresser plate 33, and a spacer collar provides proper longitudinalpositioning between the fittings 34 and the plate 33 so that upon axialmovement of member I50 the disc spring 63 is flexed about the fulcrumafforded by members 8 -8, and a parallel motion of fittings 34, bolt andplate 33 in the same direction of motion of member 63 results, the plate33 gripping the plate 3! or 32 against 8 or 8 at the end of themovement.

This construction is shown in my United States Letters Patent aforesaid,and described thereinv on page 4, beginning at line 10.

The admission and control of air pressure to the lower face of piston I0 is obtained by the control arrangement of Figure 4, a diagram of thefundamental elements and units required.

The clutch shifting piston IE! is shown in cylinder H, ready for rockingthe clutch operating lever G2 toward the up position, in which thecollar 63 of Figure 2 shifts the spring 63 toload clutch plates 3 I.

The magnet valve V, such as is shown in my U; S. Letters Patent No.2,322,479, in Figure 3 thereof, when electrically energized deliversreservoir air pressure to the cylinder II for raising the piston 10against spring I2, or is spring-biasedff so that'it shuts off thereservoir pressure androleases pressure from cylinder I I, to permitspring I2 to lower the piston I0.

The current supply to the magnet valve V passes through stop switch Sand gear lever switch 5 from the battery; and also passes throughoverrule switch S and governor switch S in parallel paths.

The piston rod 73, has a striker 74, which intersects the lock pin I6 ofstop switch S when air pressure lifts the piston I toward direct driveposition.

The air pressure delivered by the magnet valve V to line I reduces theengine throttle setting, the small piston 80 of cylinder BI having rod82 linked to bellcrank 83 pivoted to rod 84 of the fuel injector rack85, and operating through the body of spring 88. While the drawingherewith shows a fuel injector control, it is obvious to those skilledin this art that a common combustion engine throttle member could beoperated by rod 84 without exercise of invention. The term throttleherein used may be taken to describe either injector control orthrottle, as is well known. The clutch operating cylinder II is portedto air line I8, connected to the left portion of the throttle controlcylinder 8!, so that when the clutch piston I0 rises beyond the port ofline I8, the air pressure may flow to the leftward face of piston 80,equalizing that exerted on its rightward face, whereupon the restoringspring BB-returns the throttle rod 84, bellcrank 83 and rod 82 tooriginal position.

The battery current is led through the master switch 5, convenient tothe operator, and then divides through two paths, one to the governorswitch S overrule switch S and magnet valve V; the other to thegearshift lever switch S solenoid stop switch S and magnet valve V.

The accelerator pedal I20, operates a sequence of mechanically connectedelements such as lever I2I, rod I22, bellcrank I23 and the rod I24 oflost-motion device L, the casing of which is attached to rod I25 of arm83 of bellcrank 83 controlling the throttle rod 84 which is an enginefuel feed control element. The spring I26 normally transfers thrustbetween rods I24 and I25.

The pedal I20 at full throttle, strikes overrule spring I30 mountedunder it on the floor board, which increases the pedal resisting force,but the lost motion device L opens the overruling switch S breaking thecircuit to the governor and magnet valve V, which causes a transfer ofdrive from direct-drive clutch plate 3| to torque converter plate 32.

With the vehicle at rest, engine running, the

operators master switch S, being normally closed, the gear lever I ofFigure 3 being moved to forward drive position, engages the slider 40 ofFigure 2 with the teeth IBa of member I9.

Advancing the engine throttle causes the torque converter to delivertorque to shaft I0, since clutch plate 32 is normally engaged.

The governor I of Figure 4, driven by gear 30 of Figure 2 closes switchS the battery currentpassing through closed overrule switch 8 to magnetvalve V, which energized, opens reservoir pressure to cylinders II andiii. The clutch piston I8 rises to rock lever 62 to release clutch plate32 and engage direct drive plate 3|, piston first moves left in cylinder8I, to close the throttle momentarily. As soon as piston I0 uncovers theport of line IS, the air pressure equalizes on the faces of piston 80,and spring reopens .the throttle. v

" Drive thereupon continues indirect. drive; un-

less the speed of governor I50 fails to open the switch S whereupon themagnet valve circuit is broken, and the pressure directing valve V shutsoff the reservoir and releases the pressure in clutch cylinder II, sothat spring I2 resets the clutch arm 62 and collar 60 of Figure 2 toload clutch plate 32 for drive through the converter.

The momentary release of the throttle upon upshift to direct drive bymeans of the governor control serves the useful purpose of shorteningthe shift interval during which excess drag wear of the frictionclutches could otherwise occur. I do not find it necessary to apply thereactive control upon the engine throttle during the downshift toconverter drive, with this construction. The roller clutch B does nottransmit torque until rotor i! attempts to exceed shaft I0 in speed.

The accelerator pedal I20 at beyond full throttle may break the circuitto the magnet valve V, by opening the overrule switch S and thereby setaside the action of the governor I50. The driver has the option ofinitiating a downshift by pedal advancing movement, due to the feelprovided by overrule spring I30. The linkage of the pedal I20 to thelost-motion device L, and to the overrule switch S and the force ofspring I38 are so arranged that the operator feels a decided resistanceto further travel of pedal I20, just before the mechanism would openswitch S This pedal-overruling action may be set to occur at about fullthrottle setting, beyond, or somewhat below, in accordance with theselected drive and engine characteristics. As described herein,

" the preferred arrangement is to have the downshift-by-pedal effectoccur beyond the full throttle pedal setting.

When the air pressure is sliding the piston I0 to the up position, asfor direct drive, the striker I4 abuts lock pin I6 of solenoid switch Sat a travel point of piston rod I3 equivalent to a release position forboth clutch plates 3|, 32, by collar 60 of Figure 2, halting beyond thepoint.

The above described control disclosure represents a continuation in partof the subject matter of my application for Letters Patent, Serial No.299,643, filed October 16, 1939, now Patent No. 2,380,677, issued July31, 1945, in particular the showing of Figures 16 and 1'7. It isbelieved wellknown in this art to describe the mechanism of Fig. 4 whichcoordinates the movement of gearlever I40 and that of accelerator pedalI20 for overcontrol of the drive-selecting action of governor I50, inthe category of interfering devices which condition the governor action.

Referring back to Figure 1, rod 44 is connected to bellcrank lever 45 ofFigure 3 pivoted to rod 46 extending through the floorboards and pivotedto arm him of part I42 of Figure 3; and rocks bellcrank 43 pivoted torod 42 having swivel connection with the arm of shifter fork 4].

The gear lever I40 of Figure 3 is fastened to shaft I4I rocking withmounting I42 located forward in Figure l, at the operator's station. Thelever I40 and mount I42 rock fore and aft, the mounting I42 of the leverI40 permitting a small lateral motion of the mount I 42. The lever I40is guided in the E-slot of the upper portion of the casing I45 forreciprocation, and for lateral motion into the slot passages F N and "'Rfor forward, neutral and reverse shift operation.

The switch E; of Figure 3 is supported adjacent the lever I40, which isbiased toward the gear station positionsby spring I43. The striker pin16' of 3 always protrudes in the path of the striker 14 of rod 1'3,whenever the gear lever I40 is in the left, or continuous portion of theE-slot, with switch S closed. This halts the piston 10 of cylinder H inmid-position or neutral, as the air under the piston I causes it torise. The solenoid armature I6 and cam 14 of rod 13 may be regarded asan interfering device interrupting the operation of piston 10 in itsfluid pressure stroke.

The lever I49 as a transmission control member, mechanically operatesslider 40 of Figure 2 by appropriate linkages, and its actionconstitutes an improvement over the arrangement of Figure 9 of myLetters Patent U. S. 2,322,479.

A fluid torque converter of the type shown in the present demonstrationdoes not have adjustable mechanical members for varying its drivecharacteristics, which latter are therefore fixed and determined by itsfluid capacity, and by the number, spacing and shaping of its blades. Inapplying a unit of this character to a specific vehicle load and speedproblem, the working out of the factors for best efficiency of thetorque converter establishes a narrow range of converter speeds, torquecapacity and given speed ratio range, which in turn fix the speed andtorque range of the engine used to drive the vehicle through theconverter.

The work of keeping large heavy-duty vehicles in operation during anengine shortage, or in operation in the field of war where enginereplacement is a major problem calls for ingenuity in adapting enginesof differing speed and torque ranges to the drives of one specific typeof vehicle, especially when the power transmission of the vehicle hasspeed and torque response characteristics which are so narrowly limitedby the weight, and load range and allowed speed of the vehicle.Experience has shown that with a vehicle drive assembly of the abovenoted arrangements with a gasoline-fueled engine, it cannot be directlyreplaced by a slower speed diesel engine of the same horsepower rating,without a loss in both economy and performance. The problem cannot besolved by changing the rear axle ratio since this will destroy the closeharmony of the fiuid torque converter characteristics with those of thevehicle drive. The invention herewith provides for ready removal andreplacement of the engine, and the equally ready change of drive gearsbetween the engine and the power transmission assembly, which permitsthe fiuid torque converter and the clutch parts to be readily replacedwhile drive mechanism between it and the vehicle wheels remainsundisturbed, as a fixed part of the drive, although the input powermeans is changed.

For maintaining full schedule field operations, the invention hereinenables the heavy-duty vehicle to continue in indefinite, longservice'supported only by replacement engines, converters and gear pairscorresponding; eliminating further need for field supply or warehousingof various sizes of torque converters and axle gears.

In such field operations where it may be necessary to retain the torqueconverter in the vehicle and use another engine of a different powercharacteristic, the gear pair 5.6 may be replaced by a gear pair ofdiffering ratio to match the new engine to the torque converter, in thefollowing manner: the housing H30 is detached from the engine casingacross the joint shown, and this permits the withdrawal of the driveassembly with the casing 100*, since the jackshaft 2 may slide free ofcollar 4 on splines 4. The retainer 10 bolts for bearing Ill!) areremoved, permitting removal of gear 5 and shaft 2.

The casings H10 and lim are separated at X and the whole assembly to theleft, may be slidden free, since shaft I0 is only splined to clutch gear19, and shaft I with gear 6 is released from bearing llfl by release ofthe nut and screw fitting shown. The bolts holding drum 8 to shaft 1 areremoved and the new shaft with gear, replacing 6.1 installed. Thereverse of this sequence is followed with the new gear pair in place, aseparate unit assembly of jackshaft 2 and gear 5 being required. Theconvenience of being able to detach whole units of this otherwisecomplex assembly for such replacement operations is believed amplydemonstrated herein.

7 It is obvious that with the facilities provided by the invention, thevehicle so equipped, regardless of engine failure or of shop time neededfor engine repair or adjustment, can continue in effective operation forlonger periods a-wheel, and thus have its useful load-carrying lifeconsiderably extended, on a service-per-time basis. This quality is notonly important during peace when operating cost-time factors regulateprofits, but also during war when meager and scattered field servicefacilities are overloaded by the requirement for mobility, and by thefrequent losses of remount stations.

. Another important phase of the invention is that of the space'savingafforded by the angle drive grouping which places the entire powertransmission and torque conversion mechanism on the angle drivecenterline. With rear-engined power plants, there is a constant problemof finding space for cooling apparatus, accessory mechanism such asstarters, compressor systems, air conditioning machinery, specialelectrical generator equipment and the like. The present inventionrelieves the transverse power plant compartment space at the drivingside of the engine, so that the necessary width of the vehicle can beless, or the saved space can be used for accessory devices whichotherwise use up payload space elsewhere in the vehicle.

The normal power plant which includes the transmission in line with theengine has become a mass and volumetric problem with the utilization offiexible mountings to assist in absorption of torque vibrations, becauseof the great linear extension of the masses involved in thetorquesupporting system.

While the casual observer is not aware of the importance of saving a fewpounds of weight of driving parts nor that such savings are reflected insavings in bearing and casing weights, it is understood by those skilledin the art who will appreciate the teaching of the present inventionwhich provides improvement in economy, performance and extension ofuseful life of motor vehicle drives.

The arrangement herein of composite casing compartmenting for quickremoval of unit sections of gearing, clutches, converter, and shaftingwithout disturbing other members of the drive assembly is believedunique. It will be noted that the converter output roller clutch R isreadily exposed for inspection and servicing without requiring the otherunits to be disassembled; the converter unit T is also removable withthe unit R; the compartment for the clutches C may be opened also withthe detachment of units R and T; and the assembly G at the opposite endof the power transmission is likewise as readily serviced. The assemblymay also be detached bodily from attachment to the engine casing forchanging the whole assembly unit. The arrangement of bearings whichprovides full support for the driving parts is coordinated with thedivision of the sub-compartments, greatly facilitating removal,inspection and replacement, without disassembly of other units not ofimmediate concern.

The control system shown in Figure 3 is small, neat and compact. Thediesel engine fuel control rack shown, may be mechanically operatedthrough a lost-motion device, from the accelerator pedal, and during ashift from converter to direct drive, is momentarily shifted to reducethe engine speed, and promptly restored when the shifter apparatusreaches the end of travel. It will be noted that the position of theequalizer port of line 18 connected to de-throttling cylinder BI is atthe neutral stop position for the clutch servo piston rod '13. It hasnot been deemed necessary to duplicate herein the detailed constriictionof the magnet valve, solenoid neutral stop, governor and switches, sincethese are shown in my Letters Patents and applications mentioned herein.

The arrangement of parts to provide pedal feel so that the operator maydetermine and choose whether or not to overrule the governor is believedimportant, since in the operation of large vehicles in particular, theintuitive sense of the operator in observing the driving conditions isnecessary, in order to obtain the maximum usefulnessof the automaticcontrol.

These and other advantages noted elsewhere in this specification areprovided in the novel assembly described herein in demonstrating theinvention. The appended claims are drawn to cover all propermodifications and adaptations and it is not my intention to limit the,scope of the invention to the particular embodiments shown herewith,sinceone skilled in the art and made acquainted with the teachings setforth in the present specification would know how to utilize theseteachings while departing from the exact details of construction shownand described.

I'claim:

1 In power transmitting devices, a vehicle having a differential drivingaxle and an engine with its powershaft parallel thereto, selectivevariable speed drive mechanism coupling said axle and said shaft withthe axial centerline of the mechanism lying at an oblique angle to thecenterlines of said axle and said engine, and said mechanism including aplurality of ratio changing clutches concentric with said obliquelyplaced mechanism, said clutches being arranged to provide drive atdifferent speed ratios between said engine and axle fluid pressureactuating means for said clutches, a throttle for saidengine, speedresponsive control means for said fluid pressure means, fluid pressurecontrol means for said throttle effective during operation of said fluidpressure actuating means, and an accelerator pedal control mechanism forsaid throttle effective at advanced pedal positions to set aside theaction of said speed responsive control means and cause actuation of oneof said clutches with release of that one which is driving, and anarrangement of said pedal control mechanism effective to increase theresistance of the said pedal to advancing pressure prior to the advanceposition of the pedal which is effective to set aside the action of thespeed responsive means.

2. In control devices for power transmissions, in which the operatorscontrol station is remote from the apparatus to be selectivelymanipulated, a vehicle having a transversely placed engine coupled to avariable speed ratio driving mechanism placed diagonally with respect tothe centerline of said engine and coupled to a differential axle,forward drive-changing means included in said mechanism control meansfor said drive-changing means including a speed responsive deviceeffective to establish higher and lower forward speed ratio drives bysaid drive-changing means and interfering devices controlled by thedriver for overcoming and setting aside the effect of said speedresponsive device upon said mechanism, including an accelerator pedalmechanism which at a predetermined position of pedal advance iseffective to establish a lower forward driving ratio than the ratiootherwise determined by said device, and which prior to reaching of saidadvance pedal position provides additional resistance to the pressure'ofthe operators foot as a signal that if further pressure is exerted inadvancing the pedal, the aforesaid lower driving ratio shift determinedby said device will take place.

3. In the construction set forth in claim 2, the subcombination ofselective neutral, forward and reverse driving elements included in saiddriving mechanism, of driver-operated linkage for changing said drivingmechanism between forward and reverse drive by said elements and of saidlinkage having a connection effective upon said variable speed ratiocontrol means for establishing neutral drive in which said forwarddrivechanging means is rendered ineffective for given speed ranges ofsaid device.

4. In vehicle controls, variable speed ratio driving mechanismconsisting of automatically controlled forward drive-establishingmembers and of manually selective forward and reverse drive gearing, anautomatic control for said members including a' speed responsivegovernor, operatoroperable means to control the drive by said membersand said gearing including an accelerator pedal operated elementeffective beyond a given position to set aside the automatic control bysaid members and coacting with a device effective to signal the foot ofthe operator just prior to the said element attaining that position,said means further including gearing control means for establishingselective drive by said forward and reverse drive gearing operative inpredetermined settings to prevent drive by said automatically controlledforward drive-establishing members, during a given speed range of saidgovernor.

5. In power transmitting devices, a vehicle having a differentialdriving axle, an engine with a powe'rshaft parallel to the axis of saidaxle, a relatively short jackshaft serving as the power input driver ofsaid differential driving axle and located obliquely to the axisthereof, selective variable speed drive mechanism providing forward andreverse drive and coupled concentrically to said jackshaft and obliquelyto said powershaft for transmitting the drive of said engine to the saidshaft, and remotely located controls for said mechanism embodying afirst group of control members effective to select automatically thevariable speed ratios for forward drive, an automatic control apparatusfor said members including a speed-responsive governor, and a secondgroup of members manually operative to nullify the selective action ofsaid apparatus upon said first-named members and to compel a change toneutral or reverse drive by said mechanism.

6. In controls for motor vehicles, a variable speed ratio transmissioncoupling power and load shafts, a fluid pressure operated device havingthree operating positions one of which establishes neutral or no-drivewithin said transmission, a second of which establishes direct drivebetween said shafts and a third of which establishes variable ratiodrive between them, a control system including a controlling member forsaid transmission operative upon said device for causing same to occupysaid positions including a pressure-directing valve for said deviceadapted to be made operative by operation of said member, controlmechanism for said valve, and a movable stop controlled thru said systemand by movement of said member for locating said device in said neutralposition upon predetermined setting of said member.

7. In the combination set forth in claim 6 the sub-combination of a gearselecting handlever for said transmission included in said controlsystem, and of said control member of said system means made operativeby selective motion of said handlever for controlling the action of saidmovable stop.

8. In the combination set forth in claim 6, the sub-combination of amanually operable control for said system, normally movable to selectthe drive between said shafts and of said member of said control systemmade operative by such selection motion to compel neutral drive whensaid transmission control member is moved into a predetermined position.

9. In controls for motor vehicles, a variable speed ratio transmissionassembly coupling power and load shafts, said assembly embodying driveactuating members, a power plant and fuel feed control element therefor,a servo operated device for the drive actuating members of saidtransmission for establishing variable ratio drive between said shafts,control mechanism for said device, control means for said mechanismincluding a member operated conjointly with said element and including aspeed responsive ratio selector coacting with said member and operativeto cause said mechanism to operate said device to actuate saidtransmission members selectively for the driving conditions determinedby said selector and said conjointly operated member, an interruptingmeans in the path of motion of said device, and a manual control forsaid transmission effective when placed in a predetermined position toenergize said interrupting means, whereby the action of the said controlmechanism and means is set aside and the said transmission drive membersare prevented from actuation by said device.

10. In the art of vehicle drive assemblies, the combination of a vehiclehaving a differential driving axle and having an engine located adjacentthereto with its powershaft centerline parallel to the centerline ofsaid axle, driving means having a centerline intersecting saidcenterlines at an oblique angle and adapted to couple the powershaftwith the drive of said axle, said means including a fixed ratio inputcoupling constantly driven by said powershaft, drive changing mechanismdriven by said coupling and having an output shaft constantly coupled todrive said axle, selectively operable drive-transmitting power trainelements embodied in said driving mechanism'and including clutch membersadapted to couple said elements, said clutch '14 members beingselectively actuable for connecting the drive between said input andoutput shaft couplings, and operator-operable means having controlelements remotely located in the fore portion of said vehicle which areeffective to select and cause actuation of said clutch members forestablishing said selective drive connection, said means including apedal-operated device operable to initiate said selection action.

11. In a rear wheel driven vehicle, the combination with an enginetransversely mounted at the rear of the vehicle, of a transverselymounted differential axle with its centerline parallel to the centerlineof the engine, of a variable speedratio drive changing mechanism havinga drive gcenterline intersecting said centerlines at an oblique angle,power conversion couplings joining input and output members of saidmechanism to said engine and said axle respectively, said couplingsconstantly connecting said members for all drive conditions of the saidvehicle, of drive changing control means embodied in said mechanismactuable to provide different power trains between said members, ofcontrols for said drive changing means including an element se lectivelyoperable by an operator, of control devices for said drive-changingcontrol means and of linkages connecting the said devices with saidcontrols, whereby effective operator control of the obliquely locatedmechanism is afforded.

12. In the combination set forth in claim 11, the sub-combination ofsaid drive-changing mechanism embodying a fluid torque converter unitarranged to transmit forward and reverse drive between said engine andsaid axle, and of said drive changing control means being specificallyoperable to establish change between forward and reverse drive thereby,for'selected settings by said controls of said control devices.

13. In the combination set forth in claim 11, the sub-combination ofsaid control devices further including an engine-throttle controlelement for said engine, a speed responsive element adapted to coactwith said throttle control element, and a foot-operated membercontrolling said throttle control element while likewise operative tointerrupt the action of said speed responsive element for predeterminedsettings of said foot-operated member, wherein the said control devicesprovide automatic change of said drive-changing control means.

14. A vehicle having a transversely mounted engine at the rear with atransverse power shaft, wheels and wheel axles for driving the vehicle,a transverse axle housing for said axles having a centerline parallel tothat of said shaft, differential gearing in said housing adapted totransmit drive to said axles, a fixed ratio bevel gear unit driven bysaid shaft, a diagonally located power'transmission assembly arranged totransmit the power of said engine to said differential gearing, saidassembly having a diagonally located centerline intersecting thecenterlines of said shaft and said differential axle housing, saidassembly having an output member constantly coupled to the input of saiddifferential gearing and having an input member constantly driven bysaid unit, drive changing means included in said power transmissionassembly selectively operative to transmit forward and reverse drivebetween said members, to transmit a range of infinitely variable speedratios therebetween and likewise operative to disconnect the drive ofsaid assembly, and operator-operable control means for saiddrive-changing means 15 located in the forward portion ofsaid vehicleeffective to initiate the selective drive transmitting operationsdescribed for the said drivechanging means.

15. In the combination set forth in claim 14, the sub-combination of aspace arrangement wherein the said axle housing lies forward of saidengine, of elements of said drive-changing means for changing theforward drive ratio of said assembly being grouped on the saiddiagonally located assembly centerline rearward of the point ofintersection of said latter centerline with that of said engine; and ofthe said control means .for' selecting the drive provided by saidelements and the said operator-operable means so located in the forwardportion of said vehicle, being equipped with connections operable tocompel complete interruption of the drive of said assembly between saidmembers at the will of the operator.

16. In power transmission controls for vehicles, an engine, a variablethrottle for the engine, a shaft driven by said engine, a forward andreverse gear unit connected to a load shaft, an intermediate shaftadapted to drive the input of said unit, a fluid torque converterarranged to drive said intermediate shaft from said engine shaft atreduction speed ratios, adirect drive friction clutch adapted to connectsaid enginedriven shaft with said intermediate shaft, a clutch actuatoroperable to connect and disconnect said direct drive clutch, a fluidpressure servo device for operating said actuator to connect said clutchor to release same for permitting reduction drive by said converter, afluid pressure source, a valve for controlling said device by selectivedelivery of fluid pressure from said source to said device, a controlmember for said engine throttle, a control member for said unit, and aspeed-responsive mechanism, a control system for said valve including anelement perated by said first-named control member and an elementoperated by said mechanism, said elements coacting within said system tocause the valve to deliver pressure to said device or to relieve sametherefrom for connection and disconnection of said clutch, and anelement opera-ted by said second-named control member effective tointerrupt the control action of said elements upon said valve, duringperiods of predetermined speeds of said mechanism.

17. In power plants for rear-engine-mounted vehicles of the type havinga transversely located engine coupled to a power transmission assembly,a remote operator control station, an arrangement of said assemblystraddling the centerline of said engine and including a fluid torqueconverter and selective drive clutches located at one endof saidassembly, a forward-neutral-reverse gear unit and output shaft fordriving the vehicle axle located atthe-oth'er end of said assembly, abevel gear output unit driven by said engine, actuating controlmechanism for said clutches located adjacent said bevel gear at one sideof the intersection of said engine and assembly centerlines, shiftcontrol mechanism for said gearing located at the opposite end of saidassembly from said clutch control mechanism, and a driver controllocated in said station operative upon both said mechanisms consistingof a forward-neutra-l-reverse selecting lever connected mechanically tosaid shift control mechanism for said gearing and connected byelectropneumatic apparatus to said actuating control mechanism for saidclutches.

18.. In a remotely controlled vehicle drive assembly, a vehicle havingits engine, variable speed drive mechanism and final drive located atthe rear and its control station for these powerhandling elementslocated in the fore portion the'reof,a plurality of clutches of saidmechanism adapted to provide reduction or direct drive by selectiveclutching to said engine, a gear unit adapted to connect said clutchesto said final drive for forward or reverse running of said vehicle, acontrol system for said clutches including fluid pressure servo actuatedapparatus made operative to engage and disengage said clutchesalternatively so as to provide said reduction or direct drive, saidsystem including a selector for said gear unit located in said controlstation and positionable for establishing said forward, said neutral orreverse drive, the selector being freely movable to forward, neutral orreverse positions by the operator, a speed responsive control for saidapparatus arranged to provide automatic shift to said reduction ordirect drives by said clutches, and a stop device made operative by saidmotion of said selector to require disengagement of both said clutcheswhen the selector is moved to select said forward, neutral or reversedrives.

19. In controls for motor vehicles, a variable speed ratio transmissioncoupling power and load shafts, a fluid pressure operated device havingthree operating positions one of which establishes neutral or no-drivewithin said transmission, a second of which establishes direct drivebetween said shafts and a third of which establishes variable ratiodrive between them, force-applying means normally operative to bias thesaid device to occupy one of the said second or third positions, fluidpressure actuator apparatus operative to overcome said biasing means andcause the device to occupy the alternative position to that normallydetermined by said biasing means, a control system for said transmissionincluding a fluid pressure-directing valve for said actuator apparatus,including a member and including automatic forward drive controllingmechanism operative to cause alternate shifting of said device betweensaid second or third positions, and a movable stop-made operative byselected motion of said member to stop said device in the said first,neutral position during shift of said device between said second andthird positions.

20'. A variable speed ratio transmission drive for a vehicle driven byan engine, a fuel control element of said engine, a forward and reversegear train of said transmission, a selector lever operative to establishthe drive of said train, a first clutch of said transmission forconnecting said shafts at variable speed ratios, a second clutch forconnecting said shafts directly, a clutch operating mechanism forengaging one or the other of said clutches, biasing mea'nsfor' saidmechanism normally operative to hold one of the clutches engaged whilereleasing the other, a fluid servo motor adapted to overcome the saidbiasing means and release the first of said clutches and hold the secondsaid clutch engaged, a fluid-pressure supply system including a valvemovable to a first position tovent said motor and toa second position tofeed servo fluid pressure to said servo motor, biasing means for saidvalve normally tending to hold the valve in one of said positions, anautomatic control system including a control device operative toovercome the said valve biasing means and cause the valve to 0c"- cupythe other of said positions, a speed responsive governor device .of saidsystem normally 17 operative to permit the said valve biasing means tooperate in one speed range thereof and operative upon said controldevice for causing same to overcome the said biasing means while movingthe said valve to the other of said positions, an overcontrol device forsaid speed responsive device movable by said element to interrupt the21. In power transmissions and control apparatus therefor, a variableratio transmission including a pair of alternately engageable clutchesadapted to transmit direct or variable ratio drive between power andload shafts, a clutch actuator mechanism for said clutches includingbiasing spring means tending to hold one clutch engaged and the otherdisengaged at end positions of said mechanism, said mechanism having amid-position in which both said clutches are released, a fluid servomotor normally operative to shift the clutch actuator mechanism from thespring biased position to the opposite end position when fluid pressureis applied to said motor and normally operative to permit the biasingspring means to restore the mechanism to the initial biased positionwhen fluid pressure is released from said motor, a valve for feedingpressure fluid to said motor or for relieving same therefrom, a controlfor said valve, a stop mechanism for holding said clutch actuatormechanism in said mid-position, an energizing control for said stopmechanism, a control system for said transmission including a controllever movable to selected ratio drive position for establishing selecteddrives of said transmission, and a connection from said control lever tosaid energising control operative to station said stop mechanism forholding said actuator mechanism in mid-position during motion of saidlever toward selected ratio drive positions.

22. In controls for alternately engageable clutches of power drivemechanisms, in combination, a clutch operating device consisting of apiston rod, a lever moved by said rod, a shaft moved by said lever, aclutch shifting collar and a cam operated by said shaft for moving saidcollar; a biasing spring for holding said rod in one end position, apiston on said rod, a cylinder for said piston, a fluid pressure feedpassage for said cylinder connected to cause said piston to move againstsaid biasing spring during application of pressure to said passage, andto move to the other end position, a valve in control of the saidpassage, a mid-position latch for said rod, operating means for saidlatch adapted to preset said latch for holding said rod in mid-position,and a control for said valve and for said latch operative to cause saidpiston rod to move hetween the said end positions while energising saidlatch operating means.

23. In the combination set forth in claim 22, the sub-combination of avariable speed drive transmission connecting driving and driven shafts,a pair of friction clutches included in said transmission arranged foralternate engagement in order to establish direct or variable speeddrive between said shafts, a forward and reverse gear train of saidtransmission, a control linkage operable to establish forward or reversedrive of said train, a manual controller for said linkage, and aconnection from said controller to said first named control effective topreset said latch when said controller is moved toward establishing saidforward or reverse drive of said train.

' 24. In the combination set forth in claim 22, the sub-combination ofan automatic control system for said valve consisting of a biasingspring and an electrical energising circuit for said valve control, agovernor operated switch effective above a given governor'speed to closesaid circuit, and a second switch in said circuit normally biased tomaintain said circuit closed and movable to interrupt said circuit sothat said valve biasing becomes effective to re-set said valve duringintervals when said governor switch is closed.

25. In the combination set forth in claim 1,

the sub-combination of a pair of friction clutches acting as saidmembers, an arrangement of said gearing wherein both of said clutchesmay establish the forward and reverse drive of said gearing, a controlelement for said gearing embodied in said last named control means, ashifter member actuating said clutches alternately at either end of itsmotion and having a neutral-drive-determining mid-position, and acontrol device made operative by selected movement of said gearingcontrol element and effective to hold said shifter member in the saidmid-position.

26. In the combination set forth in claim 4, the sub-combination of saidmembers being a pair of alternately engaged friction clutches, anarrangement of said gearing wherein both of said clutches may transmitdrive to said gearing for establishing the forward and reverse drivethereof, a control element for said gearing embodied in said last namedcontrol means, and a control device made operative by selective movementof said gearing control element to set aside the action of saidautomatic control, for predetermined speed ranges of said speedresponsive governor.

. HANS O. SCHJOLIN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,096,541 Haltenberger Oct. 19,1937 2,162,937 Carter et al June 20, 1939 2,322,479 Schjolin June 22,1943 2,369,126 Baker Feb. 13, 1945 2,369,369 Peterson et a1 Feb. 13,1945 2,380,677 Schjolin July 31, 1945 2,435,930 Schjolin Feb. 10, 1948

